1

我正在尝试使用此代码从 db 获取特定数据

Bunts = _buntRepository.Bunts
            .Where(b => !steel.HasValue || b.SteelCode == steel)
            .OrderBy(b => b.CreationTime)
            .Skip((page - 1) * _pageSize)
            .Take(_pageSize)

实体框架为其生成以下 SQL 语句：

SELECT FIRST (5) SKIP (0)
"B"."BUNTCODE" AS "BUNTCODE", 
"B"."BUNTNAME" AS "BUNTNAME", 
"B"."BUNTDIAM" AS "BUNTDIAM", 
"B"."BUNTSTEEL" AS "BUNTSTEEL", 
"B"."BUNTCREATETIME" AS "BUNTCREATETIME"
FROM ( SELECT 
"D"."BUNTCODE" AS "BUNTCODE", 
"D"."BUNTNAME" AS "BUNTNAME", 
"D"."BUNTDIAM" AS "BUNTDIAM", 
"D"."BUNTSTEEL" AS "BUNTSTEEL", 
"D"."BUNTCREATETIME" AS "BUNTCREATETIME"
FROM "BUNTS" AS "D"
WHERE (("D"."BUNTSTEEL" = @p__linq__1) OR (("D"."BUNTSTEEL" IS NULL) AND (@p__linq__1 IS NULL)))
)  AS "B"
ORDER BY "B"."BUNTCREATETIME" ASC

此代码引发文本异常

动态 SQL 错误。
SQL 错误代码 = -804。
数据类型未知。

IBExpert 也是如此。@p__linq__1 参数似乎有问题。我该如何解决这个问题？

我正在使用火鸟 2.1.6.18547

4

1 回答 1

0

生成的用途@p__linq__1 IS NULL（实际上是发送? IS NULL到服务器的），这仅在 Firebird 2.5 中引入。

为了能够使用它，您需要升级到 Firebird 2.5，或者steel.HasValue在代码中而不是在查询中处理条件：

var query _buntRepository.Bunts
if (steel.HasValue) 
{
    query = query.Where(b => b.SteelCode == steel)
}
Bunts = query.OrderBy(b => b.CreationTime)
    .Skip((page - 1) * _pageSize)
    .Take(_pageSize);

注意：以上内容并未确认生成的查询（这似乎是一个错误）。如果您想要生成的结果，那么您需要：

if (steel.HasValue) 
{
    query = query.Where(b => b.SteelCode == steel.Value)
}
else 
{
    query = query.Where(b => b.SteelCode == null)
}
于 2014-12-27T10:50:51.513 回答